A Kato 700 type excavator in a unit of Nanning, Guangxi, has a slow movement. The repair master inspecting the hydraulic system of the machine is found to be worn and sealed between the hydraulic pump and the flow tray. After the replacement of the new parts, the problem of the slow motion of the excavator is still not solved. Therefore, the mend repair department master is found to repair it.
Summarize the causes of slow action of excavator excavators in general. There are 6 common reasons:
1. the leakage of the actuator (hydraulic cylinder, motor, etc.) is serious.
2. the filter core is blocked and the oil is not enough.
3. the valve spool of the reversing valve is badly worn with the seat.
4. the safety valve is dead or damaged.
5. pilot control oil pressure is not enough, resulting in reversing valve stem pressure is not in place.
6. the hydraulic pump has a fault inside.
Combined with the reasons for the slow fault above, diagnosis of Kato 700 excavator slow action failure:
1. after field failure analysis and inspection, the reasons for the first 5 were eliminated.
2. dismantling the hydraulic pump, it is found that the variable axis of the variable shaft which directly controls the swing of the inclined disk of the hydraulic pump has no compression at both ends. Dismantle the measurement of the variable axis and find that the error of the roundness is 0.05mm, and the roundness error of the hole is 0.1mm, so the gap is large, causing the serious leakage, so that the inclined disk can not be put to the maximum position, and then the whole family excavator can be found. The slow motion of the car appears.
3., shell the two ends of the shell hole to meet the required roundness, and turn the variable axis, then spray, and finally finish grinding, making the clearance between the hole and the hole 0.03mm.
